In the known magneto ignition control systems, the ignition timing is fixed by analog circuits which include RC circuits as well as an ignition transistor which, in the conductive state, allows ignition current to flow through an ignition coil and which, when blocked, interrupts the ignition current thereby causing a spark to be generated. Each component in an analog circuit of course has predetermined tolerances and, further, the characteristics thereof change with temperature. Thus, the ignition timing as a function of engine speed also has an undesired variation with respect to temperature. It is thus difficult to match an analog system to the requirements of an internal combustion engine.